1. Field of the Invention
The present invention relates to a drag mechanism for a tripod head. More particularly, the present invention relates to a drag mechanism for a tripod head that is particularly excellent with regard to a torque adjusting function, i.e., adjusting torque to an appropriate level for tilting and panning operations.
2. Description of the Prior Art
In several tripod heads for tilting and panning a camera as well as mounting a camera on a tripod, the tripod heads are provided with a drag mechanism capable of generating and adjusting torque in order to adequately pursue a moving objective and enhance the operational feelings of a cameraman.
A drag mechanism that employs brake shoes is well known. In this type of drag mechanism, a pair of arc brake shoes is provided and torque is generated by contacting each of the brake shoes to an inner surface of a cylindrical portion arranged in a tripod head. Increasing and decreasing the contact area of a brake shoe with the inner surface realizes torque adjustment. That is, increasing the contact area of a brake shoe enlarges the torque; on the other hand, the torque is reduced as the contact area decreases.
Japan Utility Model Publication No. 21996/1995 has proposed an improvement such as magnification of the adjustable torque amount by expanding the contact area of a brake shoe. The improvement, however, follows such a manner of adjusting torque as described above.
In the improved drag mechanism, a slider having a tapered face is inserted and extracted between ends of a pair of brake shoes. The insertion causes the brake shoes to move toward an inner surface of a cylindrical portion and the extraction causes the brake shoes to be removed from the inner surface to change the contact area.
Though the manner adopting such a slider has merit in that the mechanism is not complicated, the manner is poor with regard to fine torque adjustment, and thus, the torque adjustment is not reliable.
The present invention has an object of solving defects of the conventional drag mechanism and to provide a drag mechanism for a tripod head that is particularly excellent in a torque adjusting function, i.e., adjusting torque to the appropriate level that is needed for tilting and panning operations.
This and other objects, features and advantages of the invention will become more apparent upon a reading of the following detailed description and drawings, in which: